Mammoth Heat Pump: D013

Re: Error Code 1 / Fault Code 1 - Cooling

Code 1 = High Pressure Switch Fault

CHECKOUT

1. Check Refrigerant Pressures

• Hook-up refrigerant gauges to the system.
  • Start unit and monitor pressures.
    • Normal R-22 Pressures = 55 - 75 Suction, 200 - 275 Discharge.
    • Normal R410A Pressures = 100 - 150 Suction, 275 - 400 Discharge.
  • Check temperature rise on the water lines at the unit.
    • Normal water temperature rise = 9-15 deg.
    • High Head Pressure & Normal Temperature Rise = Refrigerant Overcharge
    • High Head Pressure & High Temperature Rise = Low Water Flow

2. Check Pressure Switch

• If refrigerant discharge pressure stays in a normal range but still shows Code 1 ⇒ Check Pressure Switch
  • Without removing wires, check for 2VAC on both sides of the pressure switch.
    • Power on Both Sides = Switch Closed
    • Power on One Side Only = Switch Open (Bad Switch)